What term describes notes added to a drawing to provide clarification for the reader?

The term that accurately describes notes added to a drawing for clarification is annotation. Annotations serve the purpose of providing additional information, context, or explanations that enhance the understanding of the visual content. This can include comments, explanations of symbols, or references to specific parts of the drawing.

While lettering, labeling, and description do involve text associated with drawings, they do not fully encompass the broader function of annotations. Lettering refers specifically to the text style used in the drawing, while labeling is the act of identifying specific elements within the illustration, and descriptions typically refer to longer texts that provide detailed information but may not be directly associated with the visual cues in the drawing. Annotation is the most comprehensive term for the added notes meant to provide clarification.